CN115051330A - In-station grounding grid overcurrent protection method and device of common grounding electrode converter station - Google Patents
In-station grounding grid overcurrent protection method and device of common grounding electrode converter station Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/28—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for meshed systems
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
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Abstract
The disclosure relates to an in-station grounding grid overcurrent protection method and device of a common grounding electrode converter station. Numerical value information of a high-speed grounding switch, the opening and closing state of a disconnecting link of a grounding electrode circuit, the current of the high-speed grounding switch and the current of the grounding electrode circuit in a converter station in the common grounding electrode direct current project is obtained; when the high-speed grounding switch and the grounding electrode circuit disconnecting link are in a closed state, and numerical value information of grounding switch current and grounding electrode circuit current meets a preset rule, the overcurrent protection function of the grounding grid is locked, the high-speed grounding switch is disconnected after a preset delay time is reached, the damage caused when common grounding electrode current flows into the grounding grid in the converter station can be reduced by finding the criterion of the overcurrent protection function of the locked grounding grid, the overcurrent protection function of the locked grounding grid is timely, and alarm indication information is sent.
Description
Technical Field
The disclosure relates to the technical field of direct current transmission engineering, in particular to an in-station grounding grid overcurrent protection method and device of a common grounding electrode converter station.
Background
Direct current transmission is used as a novel high-power long-distance transmission technology, has the characteristics of suitability for long-distance transmission, short-circuit current limitation, higher system stability, more flexible operation mode and the like, is successfully applied to multiple transmission projects in China, and plays an increasingly important role in the field of high-voltage transmission. With the implementation of the national business-to-business strategy of western and east electric power transmission, the number of direct current projects which are constructed and put into use is increased continuously, and in order to save construction cost and reduce the construction land of the direct current projects, a plurality of direct current projects which are adjacent to each other in geographic positions are constructed in a mode of sharing a grounding electrode.
The traditional earth grid overcurrent protection (76SG) of the converter station mainly aims at that the whole direct current system takes an earth switch in an inverter station as a potential restraining point under the condition that a direct current project is in a single-pole metal loop mode, and when other potential points of the direct current system have an earth fault, a large amount of direct current flows into an earth grid through the earth switch in the inverter station to cause damage to equipment. The criterion of the grounding grid overcurrent protection (76SG) is that under the mode of a single-pole earth or a single-pole metal return wire of a direct current project, the absolute value of the current (the current flowing into the grounding grid is positive) of a grounding switch in a station is larger than a fixed value, and an operating pole is locked after a period of time delay. The traditional earth grid overcurrent protection cannot effectively prevent the damage of the common earth electrode current flowing into the earth grid in the converter station, but can cause the expansion of the power failure range. The current main means for managing the risk is to establish an incoming current information confirmation mechanism, before the operation of converting the unipolar earth into metal or the unipolar earth into metal, the relevant station returns another direct current to the scheduling or common grounding electrode to check whether bipolar unbalanced current exists, and after the fact that the unbalanced current does not exist, the operation of converting the unipolar earth into the unipolar metal can be performed. The ground current information confirmation mechanism can prevent the current of the common ground electrode from flowing into the in-station ground net on the system, and can control the risk of the over-current protection action of the ground net under the general condition. However, if the field operator neglects the specified requirements (especially when the rectifier station is operated as a master station) when performing the single-pole mode of operation, or when a single-pole trip occurs at another converter station that shares the common ground during the single-pole earth/metal conversion, the common ground current may be communicated to the internal ground grid.
Disclosure of Invention
In view of the above, it is necessary to provide an intra-station grounding grid overcurrent protection method and apparatus for a common-ground converter station, which can effectively prevent a common-ground current from flowing into a common-ground converter station of the intra-station grounding grid.
In a first aspect, the present disclosure provides a method for over-current protection of an in-station grounding grid of a common grounding electrode converter station. The method comprises the following steps:
respectively acquiring the opening and closing states of a high-speed grounding switch and a grounding electrode circuit disconnecting link in a converter station in the common grounding electrode direct current project, wherein the opening and closing states comprise a closed state and an open state;
respectively acquiring numerical value information of high-speed grounding switch current and grounding electrode line current in the converter station;
and when the high-speed grounding switch and the grounding electrode circuit disconnecting link are both in a closed state, and the numerical information of the grounding switch current and the grounding electrode circuit current meets a preset rule, the overcurrent protection function of the grounding network is locked, and the high-speed grounding switch is disconnected after a preset delay time is reached.
In one embodiment, when the numerical information of the grounding switch current and the grounding electrode line current satisfies a preset rule, the latching grounding grid overcurrent protection function includes:
respectively taking absolute values of numerical information of the high-speed grounding switch current and the grounding electrode circuit current;
judging whether the absolute value of the current numerical value information of the high-speed grounding switch is larger than a first preset value or not;
judging whether the absolute value of the numerical value information of the grounding electrode line current is greater than a second preset value or not;
adding the numerical information of the high-speed grounding switch current and the grounding electrode circuit current to obtain a current sum result;
taking an absolute value of the current sum result to obtain a current sum absolute value;
judging whether the current and the absolute value are smaller than a third preset value;
and locking the overcurrent protection function of the grounding network when the absolute value of the numerical information of the current of the high-speed grounding switch is greater than a first preset value, the absolute value of the numerical information of the current of the grounding electrode circuit is greater than a second preset value, and the sum of the absolute values of the current is less than a third preset value.
In one embodiment, the first preset value and the second preset value are equal in size.
In one embodiment, the numerical information of the current of the high-speed grounding switch and the numerical information of the current of the grounding electrode circuit comprise magnitude and direction, and the direction from the disconnecting link of the grounding electrode circuit to the ground is the positive direction of the current.
In one embodiment, the high-speed grounding switch comprises a high-speed grounding switch with a built-in high-speed grounding knife switch.
In one embodiment, the method further comprises:
and when the overcurrent protection function of the grounding grid is locked and the preset time is delayed, sending out prompt information that the current of the common grounding electrode flows into the grounding grid in the station.
In a second aspect, the present disclosure further provides an in-station grounding grid overcurrent protection device for a common grounding electrode converter station. The device comprises:
the switching state acquisition module is used for respectively acquiring the switching states of a high-speed grounding switch and a grounding electrode circuit disconnecting link in a converter station in the common grounding electrode direct current project, wherein the switching states comprise a closing state and an opening state;
the current value acquisition module is used for respectively acquiring numerical value information of high-speed grounding switch current and grounding electrode line current in the converter station;
and the locking judgment module is used for locking the overcurrent protection function of the grounding grid when the high-speed grounding switch and the grounding electrode circuit disconnecting link are both in a closed state and the numerical information of the current of the grounding switch and the current of the grounding electrode circuit meets a preset rule, and disconnecting the high-speed grounding switch after a preset delay time is reached.
In a third aspect, the present disclosure also provides a computer device. The computer device comprises a memory storing a computer program and a processor implementing the method according to any of the embodiments of the present disclosure when executing the computer program.
In a fourth aspect, the present disclosure also provides a computer-readable storage medium. The computer-readable storage medium, on which a computer program is stored, which, when executed by a processor, implements the method of any one of the embodiments of the present disclosure.
In a fifth aspect, the present disclosure also provides a computer program product. The computer program product comprising a computer program that when executed by a processor implements the method of any of the embodiments of the present disclosure.
According to the embodiment provided by the disclosure, the opening and closing states of a high-speed grounding switch and a grounding electrode circuit disconnecting link in a converter station in a common grounding electrode direct current project are respectively obtained, wherein the opening and closing states comprise a closing state and an opening state; then, numerical value information of the current of the high-speed grounding switch and the current of the grounding electrode circuit in the converter station is respectively obtained; and when the high-speed grounding switch and the grounding electrode circuit disconnecting link are both in a closed state, and the numerical information of the grounding switch current and the grounding electrode circuit current meets a preset rule, the overcurrent protection function of the grounding network is locked, and the high-speed grounding switch is disconnected after a preset delay time is reached. According to the embodiment provided by the disclosure, the criterion of the overcurrent protection function of the locked grounding network, namely the high-speed grounding switch and the grounding electrode circuit disconnecting link are in a closed state, and the numerical information of the current of the grounding switch and the current of the grounding electrode circuit meets the preset rule, so that the harm caused when the common grounding electrode current flows into the grounding network in the converter station when the unipolar earth-to-earth metal or the unipolar metal is converted to the earth can be reduced, the overcurrent protection function of the locked grounding network can be timely realized, and the alarm indication information is sent out.
Drawings
In order to more clearly illustrate the embodiments of the present specification or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the specification, and other drawings can be obtained by those skilled in the art without inventive labor.
FIG. 1 is a schematic diagram of another DC engineering unbalanced current flowing into an in-station grounding grid during monopolar earth metal conversion of a DC engineering inverter station in one embodiment;
FIG. 2 is a schematic diagram illustrating the direction of an earth current flowing when an earth short fault occurs in a DC system according to an embodiment;
FIG. 3 is a current waveform diagram of an inverter station in one embodiment;
FIG. 4 is a schematic diagram illustrating the current flow when the common ground electrode grounding current flows into the station grounding grid according to an embodiment;
FIG. 5 is a diagram illustrating the current waveforms associated with the common ground electrode grounding current flowing into the in-station grounding grid in one embodiment;
FIG. 6 is a schematic flow chart of a method for over-current protection of an intra-station grounding grid of a common grounding electrode converter station in one embodiment;
FIG. 7 is a schematic flow chart of a method for over-current protection of an intra-station grounding grid of a common ground electrode converter station in one embodiment;
FIG. 8 is a schematic flow chart of a method for over-current protection of an intra-station grounding grid of a common ground converter station in one embodiment;
FIG. 9 is a logic block diagram of a method for in-station earth grid overcurrent protection for a common earth converter station in one embodiment;
fig. 10 is a block diagram of an in-station earth grid overcurrent protection device sharing an earth electrode converter station in one embodiment;
FIG. 11 is a diagram illustrating an internal structure of a computer device in one embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the disclosure and are not intended to limit the disclosure.
The direct current transmission project adopts a connection mode of a common grounding electrode, and the two loops of direct current transmission projects can influence each other under special operating conditions. As shown in fig. 1, when one of the return dc unipolar ground is operated, and another return dc is converted from the unipolar ground return to the metallic return, a part of the unbalanced current flows to the grounding circuit formed by the grounding electrode line of the other return dc inverter station and the in-station grounding switch, so that the in-station grounding grid of the other return dc inverter station flows in the current. This condition may have two serious consequences: the large current flowing into the grounding network in the station can cause damage to primary and secondary equipment; because the grounding electrode circuit knife switch has no current-breaking capacity, the knife switch can be damaged when the grounding electrode circuit knife switch is pulled open in the process of converting the earth return wire.
The traditional earth grid overcurrent protection (76SG) of the converter station mainly aims at that the whole direct current system takes an earth switch in an inverter station as a potential restraining point under the condition that a direct current project is in a single-pole metal loop mode, and when other potential points of the direct current system have an earth fault, a large amount of direct current flows into an earth grid through the earth switch in the inverter station to cause damage to equipment. The criterion of the grounding grid overcurrent protection (76SG) is that under the mode of a single-pole earth or a single-pole metal return wire of a direct current project, the absolute value of the current (the current flowing into the grounding grid is positive) of a grounding switch in a station is larger than a fixed value, and an operating pole is locked after a period of time delay.
Under the special working condition that the common grounding electrode current in the figure 1 flows into the in-station grounding grid through the grounding electrode circuit and the in-station grounding switch, the current of the in-station grounding switch reaches the action fixed value of the overcurrent protection (76SG) of the grounding grid, and the single-pole locking of the direct current engineering is caused. The direct current blocking does not reduce the damage of the ground current, and the ground current may damage the grounding grid in the station and cause the disconnecting link with load as usual, so the overcurrent protection of the traditional grounding grid cannot effectively prevent the damage of the common grounding pole current flowing into the grounding grid in the converter station, and the power failure range can be expanded.
The design of a control protection system of a direct current engineering inversion station is standard, the current of a grounding switch and the current of a grounding electrode circuit in the station are both regarded as positive directions in the direction of flowing into the ground, the absolute value of the current value represents the magnitude of the value, and the positive and negative values of the current value represent the direction of the current. Taking the switching operation between the pole 1 and the single pole earth and the single pole metal as an example, as shown in fig. 2, if the short circuit fault occurs to the ground in the low voltage bus of the rectifier station pole 1 during the process of closing the grounding switch 0040 and the grounding line disconnecting link 00500 in the inverter station at the same time. The current waveform of the inverter station at the fault moment is shown in fig. 3, the value of the current of the grounding switch in the inverter station is 600A, the value of the current of the grounding electrode line (the current of the grounding electrode line 1 + the current of the grounding electrode line 2) is 280A, the current difference between the electrode 1 and the electrode 2 is 882A, and the current direction and the current size of the grounding switch in the inverter station and the current direction and the current size of the grounding electrode line are the same and are different, and the sum of the current and the current size of the grounding switch in the inverter station and the current size of the grounding electrode line is equal to the bipolar unbalanced current. After a certain time delay, the overcurrent protection (76SG) of the grounding network in the station acts to lock the pole 1. In the process of simultaneously switching on the inverter station internal grounding switch 0040 and the grounding electrode line disconnecting link 00500, if a common grounding electrode current flows into the station internal grounding grid, the characteristics of the station internal grounding switch current and the grounding electrode line current are different from those of a direct current system with a grounding fault.
In one embodiment, as shown in fig. 4, the bipolar unbalanced current in station a is 1140A, the dc system performs the unipolar metal to unipolar ground conversion operation, and the ground switch 0040 and the ground line switch 00500 in station B are simultaneously closed. Part of the unbalanced current of the station a flows into the common ground, and the other part of the current flows into the intra-station ground grid of the station B through the ground line, the ground line disconnecting link 00500, and the intra-station ground switch 0040. The current waveform of the station B at the time of the fault is as shown in fig. 5, the value of the grounding electrode line current (grounding electrode line 1 current + grounding electrode line 2 current) is-77A, and the value of the station internal grounding switch current is 78A, which indicates that the grounding electrode line current and the station internal grounding switch current are equal in magnitude and opposite in direction. And an earth screen overcurrent protection (76SG) in the station B acts to lock the operating pole of the station B, the current flowing into the earth screen in the station does not disappear, and the 76SG acts to avoid the risk that the earth screen in the station B is in overcurrent and pulls the line disconnecting link of the earth pole with load.
In summary, the conventional earth grid overcurrent protection (76SG) of the converter station cannot effectively protect the special fault condition that the common earth electrode current flows into the earth grid in the station, and the power failure range is expanded. Comparing two fault conditions of the common grounding electrode current flowing into the grounding grid in the station and the grounding short circuit fault of the direct current system, the current of the grounding switch in the station is equal to the current of the grounding electrode line in magnitude and opposite in direction, and the current of the grounding switch in the station is unequal to the current of the grounding electrode line in magnitude and same in direction.
In view of the above problems and the analysis process, according to the embodiment provided by the disclosure, by finding out the criterion of the overcurrent protection function of the locked grounding network, that is, the high-speed grounding switch and the grounding electrode line disconnecting link are both in the closed state, and the numerical information of the current of the grounding switch and the current of the grounding electrode line meet the preset rule, the harm generated when the common grounding electrode current flows into the grounding network in the converter station when the unipolar earth-to-earth metal or the unipolar metal is converted to the earth can be reduced, the overcurrent protection function of the locked grounding network can be timely realized, and the alarm indication information can be sent out. In one embodiment, as shown in fig. 6, there is provided an intra-station grounding grid overcurrent protection method for a common grounding electrode converter station, including the following steps:
s602, respectively obtaining the opening and closing states of a high-speed grounding switch and a grounding electrode circuit disconnecting link in a converter station in the common grounding electrode direct current project, wherein the opening and closing states comprise a closing state and an opening state.
And S604, respectively obtaining numerical information of the current of the high-speed grounding switch and the current of the grounding electrode circuit in the converter station.
And S606, when the high-speed grounding switch and the grounding electrode circuit disconnecting link are both in a closed state, and the numerical information of the grounding switch current and the grounding electrode circuit current meets a preset rule, locking the overcurrent protection function of the grounding network, and disconnecting the high-speed grounding switch after a preset delay time is reached.
The function of locking the overcurrent protection of the grounding network can comprise locking the traditional overcurrent protection (76SG) of the grounding network of the converter station, namely, the function of the 76SG is closed.
Specifically, numerical information of a high-speed grounding switch in a converter station, an opening and closing state of a disconnecting link of a grounding electrode circuit, a current of the high-speed grounding switch in the converter station and a current of the grounding electrode circuit in the common grounding electrode direct current project can be respectively obtained; when the high-speed grounding switch and the grounding electrode circuit disconnecting link are both in a closed state and numerical value information of grounding switch current and grounding electrode circuit current meets a preset rule, the overcurrent protection function of the grounding grid is locked, the high-speed grounding switch is disconnected after a preset delay time is reached, and the opening and closing states of the high-speed grounding switch and the grounding electrode circuit disconnecting link can comprise a closed state and an open state.
In the station internal grounding grid overcurrent protection method for the common grounding electrode converter station, the criteria of the overcurrent protection function of the locked grounding grid, namely the high-speed grounding switch and the grounding electrode circuit disconnecting link are in a closed state, and the numerical information of the current of the grounding switch and the current of the grounding electrode circuit meets the preset rule, so that the harm generated when the common grounding electrode current flows into the station internal grounding grid of the converter station when the operation of converting the unipolar earth into the metal or the unipolar metal into the earth can be reduced, the overcurrent protection function of the shared grounding grid can be timely locked, and the alarm indication information can be sent out.
In one embodiment, as shown in fig. 7, when the numerical information of the grounding switch current and the grounding electrode line current satisfies a preset rule, the latching grounding grid overcurrent protection function includes:
and S702, respectively taking absolute values of numerical information of the high-speed grounding switch current and the grounding electrode circuit current.
S704, judging whether the absolute value of the current numerical value information of the high-speed grounding switch is larger than a first preset value or not.
And S706, judging whether the absolute value of the numerical information of the grounding electrode line current is greater than a second preset value.
And S708, adding the numerical information of the high-speed grounding switch current and the grounding electrode line current to obtain a current sum result.
And S710, taking an absolute value of the current sum result to obtain a current sum absolute value.
And S712, judging whether the current and the absolute value are smaller than a third preset value.
And S714, locking the overcurrent protection function of the grounding network when the absolute value of the numerical information of the current of the high-speed grounding switch is greater than a first preset value, the absolute value of the numerical information of the current of the grounding electrode circuit is greater than a second preset value, and the absolute value of the current is less than a third preset value.
Specifically, the absolute values of the numerical information of the high-speed grounding switch current and the grounding electrode line current can be respectively taken, and then whether the absolute value of the numerical information of the high-speed grounding switch current is greater than a first preset value or not and whether the absolute value of the numerical information of the grounding electrode line current is greater than a second preset value or not are judged. And then adding numerical value information of the high-speed grounding switch current and the grounding electrode line current to obtain a current sum result, and taking an absolute value of the current sum result to obtain a current sum absolute value. And then judging whether the current and the absolute value are smaller than a third preset value. And when the absolute value of the numerical information of the current of the high-speed grounding switch is greater than a first preset value, the absolute value of the numerical information of the current of the grounding electrode circuit is greater than a second preset value, and the absolute values of the current and the number are less than a third preset value, the overcurrent protection function of the grounding network is locked. In some embodiments, as shown in fig. 8, taking the common ground electrode dc engineering inverter side as an example, when the height grounding switch 0040 is in the closed position, the high-speed grounding switch 00401 is in the closed position, and the ground electrode line switch 00500 is in the closed position; absolute values of the current of the grounding switch in the station and the current of the grounding electrode circuit are both larger than preset I0; and the absolute value of the sum of the in-station grounding switch current and the grounding electrode line current is smaller than a preset value I1, wherein the numerical values of the in-station grounding switch current and the grounding electrode line current comprise the magnitude and the direction, the direction from the high-speed grounding switch 00401 to the ground is specified to be a positive direction, after the constraint condition is met, the grounding grid overcurrent protection 76SG is locked, and after the time delay T0, the alarm information that the common grounding electrode current flows into the in-station grounding grid is sent out, and the in-station grounding switch 0040 is disconnected.
In this embodiment, when the numerical information of the grounding switch current and the grounding electrode line current satisfies the preset rule, the overcurrent protection function of the grounding grid is locked, so that the harm caused when the common grounding electrode current flows into the grounding grid in the converter station when the unipolar earth changes metal or the unipolar metal changes earth can be reduced.
In one embodiment, the first preset value and the second preset value are equal in size, the numerical information of the high-speed grounding switch current and the numerical information of the grounding electrode line current comprise the size and the direction, and the direction from the grounding electrode line disconnecting link to the ground is the positive direction of the current.
The high-speed grounding switch comprises a high-speed grounding switch with a built-in high-speed grounding knife switch.
Specifically, the first preset value and the second preset value may be equal or unequal in magnitude, the numerical information of the high-speed grounding switch current and the numerical information of the grounding electrode line current include magnitude and direction, and the direction from the grounding electrode line switch to the ground may be specified as a positive direction of the current. In some embodiments, the high-speed grounding switch may include a high-speed grounding switch with a built-in high-speed grounding switch.
In this embodiment, the overcurrent protection function of the grounding network can be locked in time by setting the first preset value and the second preset value and specifying the numerical information of the current of the high-speed grounding switch and the positive direction of the current of the grounding electrode line.
In one embodiment, the method further comprises:
and when the overcurrent protection function of the grounding grid is locked and the preset time is delayed, sending out prompt information that the current of the common grounding electrode flows into the grounding grid in the station.
Specifically, when the overcurrent protection function of the grounding grid is locked and the preset time is delayed, the prompt message that the current of the common grounding electrode flows into the grounding grid in the station can be sent.
In the embodiment, the overcurrent protection function of the grounding grid is locked, and the prompt message is sent after the preset time is delayed, so that the overcurrent protection function of the grounding grid can be locked in time, and the alarm indication message is sent.
In one embodiment, as shown in fig. 9, there is provided an intra-station grounding grid overcurrent protection method for a common grounding electrode converter station, the method comprising the following steps:
and S902, respectively obtaining the opening and closing states of a high-speed grounding switch and a grounding electrode circuit disconnecting link in the converter station in the common grounding electrode direct current project, wherein the opening and closing states comprise a closing state and an opening state.
And S904, respectively obtaining numerical information of the current of the high-speed grounding switch and the current of the grounding electrode circuit in the converter station.
And S906, when the high-speed grounding switch and the grounding electrode circuit disconnecting link are both in a closed state, and the numerical information of the current of the grounding switch and the current of the grounding electrode circuit meets a preset rule, locking the overcurrent protection function of the grounding network.
And S908, respectively taking absolute values of numerical information of the high-speed grounding switch current and the grounding electrode circuit current.
S910, judging whether the absolute value of the current numerical value information of the high-speed grounding switch is larger than a first preset value.
And S912, judging whether the absolute value of the numerical value information of the grounding electrode line current is greater than a second preset value.
And S914, adding the numerical information of the high-speed grounding switch current and the grounding electrode line current to obtain a current sum result.
And S916, taking an absolute value of the current sum result to obtain a current sum absolute value.
And S918, judging whether the current and the absolute value are smaller than a third preset value.
S920, when the absolute value of the numerical information of the current of the high-speed grounding switch is greater than a first preset value, the absolute value of the numerical information of the current of the grounding electrode circuit is greater than a second preset value, and the absolute value of the current are less than a third preset value, the overcurrent protection function of the grounding network is locked.
And S922, when the overcurrent protection function of the grounding grid is locked and the preset time is delayed, sending a prompt message that the current of the common grounding electrode flows into the grounding grid in the station.
And S924, when the overcurrent protection function of the grounding grid is locked and the preset time is delayed, disconnecting the high-speed grounding switch.
It should be understood that, although the steps in the flowcharts of the figures are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in the figures may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of performing the steps or stages is not necessarily sequential, but may be performed alternately or alternately with other steps or at least some of the steps or stages in other steps.
Based on the same inventive concept, the embodiment of the present disclosure further provides an intra-station grounding grid overcurrent protection device for implementing the intra-station grounding grid overcurrent protection method for the common grounding electrode converter station. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the method, so specific limitations in the in-station grounding grid overcurrent protection device embodiments of one or more common grounding electrode converter stations provided below can be referred to the limitations on the in-station grounding grid overcurrent protection method of the common grounding electrode converter stations in the foregoing, and details are not repeated herein.
In one embodiment, as shown in fig. 10, there is provided an intra-station grounding grid overcurrent protection apparatus 1000 of a common earth electrode converter station, comprising: a switch state obtaining module 1002, a current value obtaining module 1004, and a locking judging module 1006, wherein:
the switching state obtaining module 1002 is configured to obtain opening and closing states of a high-speed grounding switch and a grounding electrode line disconnecting link in a converter station in a common grounding electrode direct current project, where the opening and closing states include a closed state and an open state.
And a current value obtaining module 1004, configured to obtain value information of the current of the high-speed grounding switch and the current of the grounding electrode line in the converter station respectively.
And the locking judgment module 1006 is configured to lock the overcurrent protection function of the grounding grid when the high-speed grounding switch and the grounding electrode line disconnecting link are both in a closed state and the numerical information of the grounding switch current and the grounding electrode line current meets a preset rule, and disconnect the high-speed grounding switch after a preset delay time is reached.
All or part of each module in the in-station grounding grid overcurrent protection device of the common grounding electrode converter station can be realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent of a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as shown in fig. 11. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless communication can be realized through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. The computer program is executed by a processor to implement a method for in-station earth grid overcurrent protection of a common earth converter station. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on the shell of the computer equipment, an external keyboard, a touch pad or a mouse and the like.
Those skilled in the art will appreciate that the architecture shown in FIG. 11 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices in which the disclosed aspects apply, as a particular computing device may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.
In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the above-described method embodiments when executing the computer program.
In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which computer program, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.
In an embodiment, a computer program product is provided, comprising a computer program which, when being executed by a processor, carries out the steps of the above-mentioned method embodiments.
It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, presented data, etc.) referred to in the present disclosure are information and data that are authorized by the user or sufficiently authorized by each party.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, databases, or other media used in the embodiments provided by the present disclosure may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high-density embedded nonvolatile Memory, resistive Random Access Memory (ReRAM), Magnetic Random Access Memory (MRAM), Ferroelectric Random Access Memory (FRAM), Phase Change Memory (PCM), graphene Memory, and the like. Volatile Memory can include Random Access Memory (RAM), external cache Memory, and the like. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others. The databases involved in embodiments provided by the present disclosure may include at least one of relational and non-relational databases. The non-relational database may include, but is not limited to, a block chain based distributed database, and the like. The processors referred to in the embodiments provided in this disclosure may be general purpose processors, central processing units, graphics processors, digital signal processors, programmable logic, quantum computing based data processing logic, etc., without limitation.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present disclosure, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present disclosure. It should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the concept of the present disclosure, and these changes and modifications are all within the scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the appended claims.
Claims (10)
1. An in-station grounding grid overcurrent protection method for a common grounding electrode converter station is characterized by comprising the following steps:
respectively acquiring the opening and closing states of a high-speed grounding switch and a grounding electrode circuit disconnecting link in a converter station in the common grounding electrode direct current project, wherein the opening and closing states comprise a closed state and an open state;
respectively acquiring numerical information of high-speed grounding switch current and grounding electrode circuit current in the converter station;
and when the high-speed grounding switch and the grounding electrode circuit disconnecting link are both in a closed state, and the numerical information of the grounding switch current and the grounding electrode circuit current meets a preset rule, the overcurrent protection function of the grounding network is locked, and the high-speed grounding switch is disconnected after a preset delay time is reached.
2. The method of claim 1, wherein when the numerical information of the grounding switch current and the grounding electrode line current meets a preset rule, the function of locking the grounding grid overcurrent protection comprises the following steps:
respectively taking absolute values of numerical information of the high-speed grounding switch current and the grounding electrode circuit current;
judging whether the absolute value of the current numerical value information of the high-speed grounding switch is larger than a first preset value or not;
judging whether the absolute value of the numerical value information of the grounding electrode line current is greater than a second preset value or not;
adding the numerical information of the high-speed grounding switch current and the grounding electrode circuit current to obtain a current sum result;
taking absolute values of the current and the sum result to obtain current and sum absolute values;
judging whether the current and the absolute value are smaller than a third preset value;
and locking the overcurrent protection function of the grounding network when the absolute value of the numerical information of the current of the high-speed grounding switch is greater than a first preset value, the absolute value of the numerical information of the current of the grounding electrode circuit is greater than a second preset value, and the sum of the absolute values of the current is less than a third preset value.
3. The method of claim 2, wherein the first and second preset values are equal in size.
4. The method of claim 2, wherein the numerical information of the high-speed grounding switch current and the numerical information of the grounding electrode line current comprise magnitude and direction, and the direction from the grounding electrode line switch to the ground is the positive direction of the current.
5. The method of any one of claims 1 to 4, wherein the high speed grounding switch comprises a high speed grounding switch with a built-in high speed grounding knife switch.
6. The method of claim 1, further comprising:
and when the overcurrent protection function of the grounding grid is locked and the preset time is delayed, sending out prompt information that the current of the common grounding electrode flows into the grounding grid in the station.
7. An in-station grounding grid overcurrent protection device of a common grounding electrode converter station, which is characterized by comprising:
the switching state acquisition module is used for respectively acquiring the switching states of a high-speed grounding switch and a grounding electrode circuit disconnecting link in a converter station in the common grounding electrode direct current project, wherein the switching states comprise a closing state and an opening state;
the current value acquisition module is used for respectively acquiring numerical value information of high-speed grounding switch current and grounding electrode line current in the converter station;
and the locking judgment module is used for locking the overcurrent protection function of the grounding grid when the high-speed grounding switch and the grounding electrode circuit disconnecting link are both in a closed state and the numerical information of the current of the grounding switch and the current of the grounding electrode circuit meets a preset rule, and disconnecting the high-speed grounding switch after a preset delay time is reached.
8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method of any of claims 1 to 6.
9. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method of any one of claims 1 to 6.
10. A computer program product comprising a computer program, characterized in that the computer program realizes the steps of the method of any one of claims 1 to 6 when executed by a processor.
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| CN117254436A (en) * | 2023-11-20 | 2023-12-19 | 中国南方电网有限责任公司超高压输电公司广州局 | Grounding electrode line protection method, device and equipment for common grounding electrode converter station |
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